Figure 4

Characterization of HIV-1 proviral DNA encoding the Vpu S52/56 mutant. HeLa cells were transfected with HIV-1-WT, HIV-1-∆Vpu or HIV-1-Vpu^D52/56 proviral DNA (pNL4.3-Ada-GFP backbone). Transfected cells and virus-containing supernatants were analyzed by Western blot using the indicated antibodies (A). Relative viral particle efficiency. The particle release efficiency of HIV-1-WT was set at 100% (average of 3 independent experiments) (B). Analysis of cell-surface BST2 expression by flow cytometry (C). Data are representative of 3 independent experiments. PHA and IL-2 activated primary CD4⁺ T cells were infected with HIV-1-WT, HIV-1-∆Vpu, or HIV-1-Vpu^D52/56 virus at an MOI of 1. At different time points post infection, cells were collected for flow cytometric analysis of CD4 and BST2 expression (D). Data is shown for cells collected at 3-dpi. Relative BST2 and CD4 levels at 3-dpi on p24^- (open bar) and p24⁺ (filled bar) cells are shown (MFI on p24-negative = 100%; n = 3). Infectious virus production was determined in supernatants as described in Figure 1(E). Data are representative of 3 independent experiments. Error bar represents SD; * p ≤ 0.05, ** p ≤ 0.005, N.S.: not significant.